n-(1,3-dimethylbutyl)-n′-phenyl-p-phenylenediamine

6-PPD (Antioxidant 4020) is an antioxidant that is the most commonly used additive in rubber and enters the environment through large emissions of tire wear particles. 6-PPD can induce neurodegeneration in Caenorhabditis elegans.

6PPD-Q (6PPD-Quinone) is an environmental pollutant that can target CNR2, CNR1, AA2AR, LCAT and TRPA1. Among them, CNR2 has the highest binding affinity and may act as a CNR2 receptor agonist to activate cannabinoid receptors. 6PPD-Q can damage the sperm quality and induce the impairment of male reproductive ability in mice. 6PPD-Q can induce intestinal inflammation and barrier damage by disrupting mitochondrial function, reducing neuronal glycolytic metabolites and TCA cycle intermediates, and exacerbating α-synuclein (α-syn) aggregation.